.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
.\"
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.\" References consulted:
.\"     Linux libc source code
.\"     Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
.\"     386BSD man pages
.\" Modified Sat Jul 24 19:23:25 1993 by Rik Faith (faith@cs.unc.edu)
.\" Modified Mon May 27 21:37:47 1996 by Martin Schulze (joey@linux.de)
.\"
.TH GETPW 3 2021-03-22 "GNU" "Linux Programmer's Manual"
.SH NAME
getpw \- reconstruct password line entry
.SH SYNOPSIS
.nf
.BR "#define _GNU_SOURCE" "             /* See feature_test_macros(7) */"
.B #include <sys/types.h>
.B #include <pwd.h>
.PP
.BI "int getpw(uid_t " uid ", char *" buf );
.fi
.SH DESCRIPTION
The
.BR getpw ()
function reconstructs the password line entry for
the given user ID \fIuid\fP in the buffer \fIbuf\fP.
The returned buffer contains a line of format
.PP
.in +4n
.EX
.B name:passwd:uid:gid:gecos:dir:shell
.EE
.in
.PP
The \fIpasswd\fP structure is defined in \fI<pwd.h>\fP as follows:
.PP
.in +4n
.EX
struct passwd {
    char   *pw_name;       /* username */
    char   *pw_passwd;     /* user password */
    uid_t   pw_uid;        /* user ID */
    gid_t   pw_gid;        /* group ID */
    char   *pw_gecos;      /* user information */
    char   *pw_dir;        /* home directory */
    char   *pw_shell;      /* shell program */
};
.EE
.in
.PP
For more information about the fields of this structure, see
.BR passwd (5).
.SH RETURN VALUE
The
.BR getpw ()
function returns 0 on success; on error, it returns \-1, and
.I errno
is set to indicate the error.
.PP
If
.I uid
is not found in the password database,
.BR getpw ()
returns \-1, sets
.I errno
to 0, and leaves
.I buf
unchanged.
.SH ERRORS
.TP
.BR 0 " or " ENOENT
No user corresponding to
.IR uid .
.TP
.B EINVAL
.I buf
is NULL.
.TP
.B ENOMEM
Insufficient memory to allocate
.I passwd
structure.
.SH FILES
.TP
.I /etc/passwd
password database file
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.ad l
.nh
.TS
allbox;
lbx lb lb
l l l.
Interface	Attribute	Value
T{
.BR getpw ()
T}	Thread safety	MT-Safe locale
.TE
.hy
.ad
.sp 1
.SH CONFORMING TO
SVr2.
.SH BUGS
The
.BR getpw ()
function is dangerous as it may overflow the provided buffer
.IR buf .
It is obsoleted by
.BR getpwuid (3).
.SH SEE ALSO
.BR endpwent (3),
.BR fgetpwent (3),
.BR getpwent (3),
.BR getpwnam (3),
.BR getpwuid (3),
.BR putpwent (3),
.BR setpwent (3),
.BR passwd (5)
.SH COLOPHON
This page is part of release 5.13 of the Linux
.I man-pages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
\%https://www.kernel.org/doc/man\-pages/.
